Haptics is a tactile and force feedback technology that takes advantage of a user's sense of touch by applying haptic feedback effects (i.e., “haptic effects”), such as forces, vibrations, and motions, to the user. Devices, such as mobile devices, touchscreen devices, touchpad devices and personal computers, can be configured to generate haptic effects. In general, calls to embedded hardware capable of generating haptic effects (such as actuators) can be programmed within an operating system (“OS”) of the device. These calls specify which haptic effect to play. For example, when a user interacts with the device using, for example, a button, touchscreen, touch pad, lever, joystick wheel, or some other control, the OS of the device can send a play command through control circuitry to the embedded hardware. The embedded hardware then produces the appropriate haptic effect.
In an automotive environment, haptics can provide tactile feedback to help create a more confident and safe user experience in an automotive environment. Automotive applications of haptics have included rotary knobs, joysticks, touch pads and touch screens. The use of touchscreens in the automotive environment is increasing. Touchscreens are a natural interface for navigation systems, and tactile feedback is an excellent complement-improving the overall touchscreen usability as well as specific features of the navigation system human-machine interface. Users experience more intuitive interactions, reduced glance time for improved safety, and space-saving designs. The touch-screen buttons deliver a tactile pulse the user can actually feel through the screen, since the screen is mounted on a suspension that permits movement of the screen, allowing the user to select an icon with a quick glance and touch of the screen. Furthermore, with the use of proximity—sensing technology, a hand can be detected as it approaches the touch screen. When the icon is pressed, the screen pulses to acknowledge the command, allowing one to keep their eyes safely on the road. Thus the physical feedback of a haptic touch screen or touch pad allows the driver to operate the system without looking at the screen or pad. The Cadillac CUR and the Acura RLX On-Demand Multi-Use Display™ are two automotive haptic touch screen applications. The Lexus NX utilizes a haptic touch pad application.
The touch screens used in the automotive environment are large displays and can be heavier than other haptic touch screens. For example, a 10-inch display may be desired and can weigh around 500 g (heavy) since the system may include a LCD secured to the touch panel by optical bonding for better visibility. The touch screen or panel may be referred to as a floating screen, as it is mounted on a suspension system to allow the screen to move as the haptic effects are generated. To provide haptics to a floating system device, low travel (motion) and high force (for acceleration) is require. As moving masses, such as the screen and its assembly, become larger and/or heavier (100 grams to 2 Kilograms), the force required rises above what cost effective push pull solenoids can provide.
Currently there are no cost effective solutions to provide haptics when the moving mass of the touch screen or panel is greater than 300 grams. The accepted approach is to use multiple solenoid or piezoelectric actuators. A touch screen panel with a moving mass is also a complex design as it is dependent on the operation of multiple components working together to create the haptic effect.
Embodiments hereof relate to an amplification mechanism for a single actuator, such as an inexpensive push pull solenoid actuator, in order to enable haptics on larger or heavier form factors and the moving mass sizes can range from 200 gram to 2 Kgram. Using a single actuator with an amplification mechanism instead of using multiple actuators results in a cost effective and less complicated design.